Comments:
1. Type EC/DSCT (contact binary or Delta Scuti star) with the period of
0.07443 days
in the ASAS-3 catalog. Actually it is a DSCT(B) star.
| Mode |
Frequency, c/d |
Semi-amplitude V, mag |
Period, days |
Epoch, JD |
| f0 |
13.43542 |
0.126 |
0.0744301 |
2453600.043 |
| f1 |
17.27023 |
0.062 |
0.0579031 |
2453600.049 |
The period ratio of the first overtone and fundamental modes is
P1/P0 = 0.7780.
B–V = 0.320 (Tycho2), J–H = 0.204 (2MASS).
ROTSE-I/NSVS data gives similar results.
2. Type DSCT with the period of 0.228712 days in the ASAS-3
catalog.
Actually it is a DSCT(B) star.
| Mode |
Frequency, c/d |
Semi-amplitude V, mag |
Period, days |
Epoch, JD |
| f0 |
4.372259 |
0.213 |
0.2287147 |
2453600.173 |
| f1 |
5.739401 |
0.071 |
0.1742342 |
2453600.055 |
| f1 + f0 |
10.11165 |
0.039 |
0.0988958 |
2453600.097 |
| f1 - f0 |
1.36715 |
0.029 |
0.73145 |
2453600.390 |
| f1 + 2f0 |
14.48392 |
0.023 |
0.0690421 |
2453600.056 |
The period ratio of the first overtone and
fundamental modes is P1/P0 = 0.7618 .
J–H = 0.184 (2MASS).
3. Type DSCT with the period of 0.077459 days in the ASAS-3 catalog.
Actually it is
a
DSCT(B) star.
| Mode |
Frequency, c/d |
Semi-amplitude V, mag |
Period, days |
Epoch, JD |
| f1 |
12.91006 |
0.128 |
0.0774590 |
2453600.046 |
| f2 |
16.01309 |
0.017 |
0.0624489 |
2453600.022 |
| f2 + f1 |
28.92313 |
0.008 |
0.0345744 |
2453600.038 |
The period ratio of the second and first overtone
modes is P2/P1 = 0.8062 .
B–V = 0.414 (Tycho2), J–H = 0.127 (2MASS).
4. Type DSCT with the period of 0.107193 days in the ASAS-3 catalog.
Actually it is a
DSCT(B) star.
| Mode |
Frequency, c/d |
Semi-amplitude V, mag |
Period, days |
Epoch, JD |
| f0 |
9.328933 |
0.180 |
0.1071934 |
2453600.038 |
| f1 |
12.171210 |
0.051 |
0.0821611 |
2453600.018 |
| f1 + f0 |
21.50015 |
0.025 |
0.0465113 |
2453600.024 |
| f1 - f0 |
2.842290 |
0.013 |
0.351829 |
2453600.300 |
The period ratio of the first overtone and
fundamental modes is P1/P0 = 0.7665.
B–V = 0.417 (Tycho2), J–H = 0.172 (2MASS).
5. Type DSCT with the period of 0.149089 days in the ASAS-3 catalog.
Actually it is a
DSCT(B) star.
| Mode |
Frequency, c/d |
Semi-amplitude V, mag |
Period, days |
Epoch, JD |
| f0 |
6.707367 |
0.091 |
0.1490898 |
2453600.025 |
| f1 |
8.867599 |
0.066 |
0.1127701 |
2453600.011 |
| f1 + f0 |
15.57492 |
0.021 |
0.0642058 |
2453600.013 |
The period ratio of the first overtone and
fundamental modes is P1/P0 = 0.7564.
B–V = 0.402 (Tycho2), J–H = 0.148 (2MASS).
6. Type DSCT with the period of 0.176448 days in the ASAS-3 catalog.
Actually it is a DSCT(B) star.
| Mode |
Frequency, c/d |
Semi-amplitude V, mag |
Period, days |
Epoch, HJD |
| f1 |
5.66738 |
0.071 |
0.1764484 |
2453745.115 |
| f2 |
7.10332 |
0.055 |
0.1407792 |
2453745.077 |
| f1+f2 |
12.77076 |
0.010 |
0.0783039 |
2453745.012 |
The period ratio of the second and first overtone
modes is P2/P1 = 0.7978.
B–V = 0.399 (Tycho2), J–H = 0.149 (2MASS).
The ROTSE-I/NSVS data (Wozniak et al. 2004) with photometric correction flags (usually
rejected) were kept for the analysis.
Remarks:
I present an investigation of six known DSCT variables. The variability of these
stars
was reported by Pojmanski (2002).
I re-analysed ASAS-3 and NSVS data using the period-search software developed by
Dr. V.P. Goranskij for Windows environment.
According to ASAS-3 (Pojmanski 2002) and ROTSE-I/NSVS (Wozniak et al. 2004) data,
the variables are high-amplitude double-mode Delta Scuti stars.
The period ratios P1/P0 and P2/P1 are
typical for radially pulsating high-amplitude
double-mode Delta Scuti stars (Petersen & Christensen-Dalsgaard 1996).
In certain cases, multiple frequencies or frequencies connected with interactions
between the two main modes were found (see the Comments).
References:
Petersen, J.O., Christensen-Dalsgaard, J., 1996, Astron. and Astrophys., 312, 463
Pojmanski, G., 2002, Acta Astronomica, 52, 397
Wozniak, P.R., Vestrand, W.T., Akerlof, C.W., et al., 2004, Astron. J., 127, 2436
